m68k: mac: Remove unused yday in unmktime()

When building with W=1:

    arch/m68k/mac/misc.c: In function ‘unmktime’:
    arch/m68k/mac/misc.c:557:33: warning: variable ‘yday’ set but not used [-Wunused-but-set-variable]
      557 |         int days, rem, y, wday, yday;
	  |                                 ^~~~

Fix this by removing the unused variable and assignment.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/b25c42eac8beb0862f1b2041e817cb421ec66b4e.1694613528.git.geert@linux-m68k.org

arch/m68k/mac/misc.c

@@ -554,7 +554,7 @@ static void unmktime(time64_t time, long offset,
 		/* Leap years.  */
 		{ 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 }
 	};
-	int days, rem, y, wday, yday;
+	int days, rem, y, wday;
 	const unsigned short int *ip;
 
 	days = div_u64_rem(time, SECS_PER_DAY, &rem);
@@ -592,7 +592,6 @@ static void unmktime(time64_t time, long offset,
 		y = yg;
 	}
 	*yearp = y - 1900;
-	yday = days; /* day in the year.  Not currently used. */
 	ip = __mon_yday[__isleap(y)];
 	for (y = 11; days < (long int) ip[y]; --y)
 		continue;